Apparatus for wireless transmission of energy.



F. H. MILLENER.

APPARATUS FOR WIRELESS TRANSM|S SION OF ENERGY. APPLICATION FILED APR 29, I91].

1 06,352. Patented Nov. 28, 1916.

3 SHEETSSHEET I.

WITNESSES: INVENTOR.

F. H. iVHLLENER.

APPARATUS FOR WIRELESS TRANSMISSION OF ENERGY.

APPLICATION FILED APR. 29.191].

- Patented Nov. 28, 1916.

3 SHEETS-SHEET 2:

INVENTOR.

WITNESSES.-

F. H. MILLENER.

APPARATUS FOR WIRELESS TRANSMISSION OF ENERGY. APPLICATI I D APR. 29- I9II.

7 1,206,352. I Patented Nov. 2 16.

. 3SHEETS-SH I I IIIIIIIII IIIII f ATTORNEYS UNITED STATES PATENT OFFICE.

FREDERICK HOYER MILLENER, OF OMA'HA, NEBRASKA.

APPARATUS FOR WIRELESS TRANSMISSION OF ENERGY.

Application filed April 29, 1911.

To all whom it may concern: v

Be. it known that I, FREDERICK HOYER MlLLENEn, a citizen of the United States of America, and residing at Omaha, county of Douglas, State of Nebraska,.have invented certain new and useful Improvements in Apparatus for Wireless Transmission of Energy.

This invention pertains to wireless or space transmission of energy, and involves the use of an energizing circuit in which is included an arc, for converting a direct into an alternating current, as made known by Duddell.

The leading feature of the present invention resides in a method of and means for suppressing the hissing of the are, which hissing is attended with variation in the potential difi'erence between the electrodes, and with other consequences which are quite undesirable, particularly in telephonic transmission.

In the accompanying drawings I have illustrated the invention as embodied in apparatus for telephonic communication, but it is equally applicable to telegraphic transmission, signaling, etc. or in fact to the transmission of. energy, to be utilized in or by any suitable receiving and translating device, or apparatus.

In these drawings: Figure 1 is a diagrammatic view of the complete apparatus, with parts conventionally represented; Fig. 2, a sectional elevation and projected end view of one of the electrodes employed in the production of the arc; Fig. 3, is an elevation of a portion of the apparatus, partly in section, illustrating the manner of cooling one electrode of each pairyFig. 4 is an elevation of a variable inductance by which the tuning of the apparatus is eiiected; Fig. 5 is a perspective view of the telephone transmitters and transformers, automatic switch, etc., as assembled for use in this transmission system; and Fig. 6, a similar view with the parts shut in or inclosed by suitable cases or cabinets.

Referring first to Fig. 1, a general arrangement of parts of the system will be explained, after which details'of construction will be pointed out.

1 indicates a conductor connected with the negative terminal of a generator or Specification of Letters Iatent.

Patented Nov. 28, 1916.

Serial No. 624,118.

source, 2, of direct electriccurrent, which current is preferably of an electromotive force of 220 volts or more.

3 indicates an inductively wound choke coil introduced in the leads or conductors of said source, 2, at a point between said source and the primary 4 of. a transformer, with one extremity of which primary 4 the conductor is electrically connected, as shown. The purpose of this choke coil 3 is to pre vent the high frequency oscillations generated in the circuit at a point beyond the coil from flowing back into the generator or source, 2.

5 indicates a variable resistance, 1n circuit with the primary 4 of the transformer.

6, 7, 8, 9, 10 and 11 indicate negative electrodes, which may be of any electrically conductive material, but which I find it expedient or satisfactory to make of carbon.

12, 13, 14, 15, 16 and 17 indicate heavy copper electrodes, which in the arrangement illustrated are positive electrodes placed in arcing relation to the negative electrodes 6, 7 8, 9, 10 and 11. These positive electrodes, as will be more fully explained hereafter, are made hollow, and provided with means for keeping them cool, and are designed to encompass the upper extremities of the c l negative electrodes, and hence to surround and inclose the arcs which form between the negative and positive electrodes. Each positive electrode is connected with the succeeding negative electrode, so that the several electrodes are in series and in alternation as to polarity, the last positive electrode, 17, of the series being electrically connected, through the choke coil 3 and a conductor 31, with the positive brush or terminal of the generator or source, 2, of electric energy.

18 to 29, inclusive, indicate pipes or tubes, designed to provide for an automatic circulation of water or other cooling medium from a tank or reservoir 30, into and through the positive electrodes 12 to 17, inclusive, and back to the reservoir.

33 indicates the secondary coil or winding of the transformer, of which 4 is the primary, as above noted.

34 indicates a variable condenser, with one member of which is connected one terminal of the secondary winding 33, the other member being adjustably connected with a of the second extremity of the secondary winding-33 of the transformer is made with the inductance and capacity 35, as indicated. Branching from the conductors 31 and 1 are conductors 31 and 1, containing, re-

spectively, condensers 38 and 39, each advisably of two microfarad capacity, or thereabout, the conductor 31 also containing a switch or circuit closer 61, by which the shunt, of which the conductors 31 and 1 constitute part, may be completed or broken at will.

40, 41, 42, 43, 44 and 45 indicate the secondaries of six open-core transformers, which secondaries are arranged in parallel between the conductors 31 and 1'. All these secondaries or windings are of like ohmic resistance, having the same number of turns of wire of the same kind and cross section. The primaries 46, 47, 48, 49, and 51 of said transformers are similarly of likewinding and ohmic resistance, and are connected in parallel between the conductors 52 and 52 of a local battery or source, 52, of elec tric energy, each primary including in the bridge between said conductors, a very low resistance, air-cooled transmitter, said transmitters being indicated at 53, 54, 55, 56, 57 and 58; and including also tubes 32 extending from a megaphone or amplifying horn 60 to the transmitters.

The transmitter here represented and about to be described, is made the subjectmatter of a separate application filed November 7, 1912, Serial No. 730,023, and no claim is herein made to the same per se. It is described merely with a view to disclosure sufficient to enable one to practice and use the invention which is here claimed.

The megaphone comprises a mouth-piece 59 of usual form, a horn 60 of funnel shape, and a plurality of tubes 32 spaced at equal angular distances about the axis of the funnel-shaped section 60, and screwed into or otherwise secured in the end closure at the large end of said funnel-shaped section 60. These tubes are of uniform length, diameter and thickness, and] made of like material, andthe open end of each screwed into the flange of the horn or section 60 bears precisely the same relation to said horn as do the others of the series, and the sound waves within the horn therefore divide between or pass equally into each of the several tubes. At the opposite end each tube 32 carries one or another of the telephone transmitters 53, 54, 55, 56, 5.? and 58 above referred to. The

mouth-piece 59 serves to gather and direct the .sound waves into the megaphone, while fee the" large horn or funnel-shaped section 60 thereof serves-"to amplify the sound promanner, and the frame itself rests on hard v rubber, or other suitable insulating material.

The positive wire 52 is connected to the other side of the microphone. The casing of each transmitter is or may be the usual Bell telephone case, commercially known as No. 226, with suitable insulation. The microphone button may be that of the commercial Bell telephone, known as No. 3 low resistance, and a heavier metallic diaphragm should be substituted for the diaphragm of ordinary commercial instruments. It is to be understood that in using or referring to these portions of commercial instruments, they are used or described merely as convenient parts readily obtainable, but may be replaced in practice by others specially designed and constructed, and the general characteristicsare set forth here merely for the purpose of better enabling others to 7 practice my invention.

It will be seen from the foregoing description that the telephone circuit is made up of six couples, each couple consisting of a low-resisting microphone and the primary of a transformer, coupled in series with each other, these six couples being connected in parallel betweenthe terminals of said local diameter of the main body or cylinder of the electrode, to leave a space 62 between the two on all sides, the lower edges or extremities of the inner and outer cylinders being joined as indicated. The cup or inner cylinder 62 should be of a diameter of about one and one-half times that of the negative electrode, which latter extends into said cup or inner cylinder, and is arranged with its rounded upper extremity substantially in the focal point or center of the hemispherical top thereof, as indicated in Figs. 1 and 3, though the actual adjustment will vary according to working conditions generally, and may be changed from time to time as required. 18 indicates a tube of suitable material passing through the cap or closure at the top of the hollow electrode, its lower end reaching to a point slightly above the hemispherical top of the inner cup or cylinder 62. 24 indicates an outlet pipe or connection carried by said cap or top closure of the electrode. By means of these inlet and outlet connections water may be introduced at the top of the electrode, and caused to descend to its lower part, where, coming in contact with the hemispherical top of the inner cylinder or cup 62, it takes up the heat thereof, and by reason of its consequent expansion rises to and flows out through the outlet 24, according to the well known laws governing the circulation of liquids under the influence of heat. The electrode illustrated in Fig. 2 is the electrode 12 of Figs. 1 and 3, and the inlet and outlet pipes or tubes are designated to correspond with said figures, but it is to be understood that the construction of all the positive electrodes is identical. Ordinarily, a plurality of pairs of electrodes will be employed, arranged as above explained in connection with Fig. 1, and an inlet tube for cold water and an outlet for the heated water, will be provided valve 66, the shell of which opens through the base or bottom of the reservoir 30, so that by adjusting said 'valve 66 the flow of water into and through the pipes 18, 19, 20, 21, 22 and 23 (Fig. 1) may be varied and controlled as desired, Tubes 24, 25

and 26, as shown in Fig. 3, and additional tubes 27, 28 and 29, seen in Fig. 1, connect the upper ends of the positive electrodes with the upper portion of the reservoir. That portion of all the tubes between the base or bottom of the reservoir and the tops of the electrodes I preferably make of rubber or other flexible substance, to provide for theready manipulationand adjustment of the positive electrodeswithout interference with or injury to the tubes.

As indicated in Figs. 1 and 3, the outlet tubes 21, 25, 26, 27, 28 and 29 are carried to a poiift materially above the bottom 'of the reservoir 30, and the portions 63, 64, 65, above the bottom of said reservoir are preferably made of copper and quite thin, and advisably carried on the exterior of the reservoir, but arranged to pass into the same through a wall thereof. The purpose of this construction and arrangement is to utilize the exposed portions of these return tubes as radiators exposed to the surrounding atmosphere, and hence giving oif thereto a large percentage of the heat absorbed by the waterwhen in the hollow electrode. As the water cools in the reservoir, it falls to the lower part thereof, and passes by the valve 66 to the tubes 18, etc., connected therewith. In this way a continuous circulation I is autoi'natically maintained, and the positive electrodes are thus kept cool. This is of great importance, particularly as to the hemispherical upper portion of the inner cup or cylinder, between which and the upper end of the negative electrode the arc is formed when the apparatus is in operation. The. vertical measurement of this inner cup or cylinder may vary, but it is deemed advisable that it be at least equal to its horizontal diameter.

It is well known that an are burning in the presence of oxygen, or in an atmosphere containing oxygen, will at times hi'ss, and it is also known that when the hissing occurs there is a marked decrease in the difference of potential between the electrodes. This drop in potential, or any considerable variation therein, interferes in greater or less degree with the operation of a wireless transmission apparatus in which the arc is employed to convert, or aid in converting, a direct current into an alternating current of a high number of cycles. Where several arcs are so employed, some or all commonly go out or cease to burn when the hissing begins. Such hissing is peculiarly detrimental when it occurs in a system of the character here described, used for speech transmission, because in addition to its other bad effects, the hissing of the are in great measure drowns the sound waves produced by the voice of the speaker, and precludes a clear transmission and the certain and distinct hearing and interpretation thereof, .at the receiving point of the system. To prevent this hissing and multiply the oscillations incident to the use of an arc in the energizing circuit, it has been proposed to envelop the arc or arcs in an atmosphere of hydrogen or other gas, or otherwise to exclude oxygen from contact with the arc, the crater, or the vapor generated in and by the arc. While such means will give satisfactory results, and while I have in another application described a simple and eflicient way of producing and applying such gas, I have discovered that if the positive electrode be kept cool, and the negative electrode be surrounded thereby, from its upper or arcing extremity downward to a reasonable point or distance, hissing of the arc may be equally well prevented, and without the necessity of any other provision or apparatus. The suppression of the hissing I believe to be due to the fact that with the positive electrode kept cool there is an almost entire absence of fusion of the electrode, or of the formation of metallic globules, roughnesses or projections,

I main groups or sections.

depressions or pittings, which might, and in fact do, produce a variation in the length of the arc, accompanied by a variation in the difference of potential between the electrodes; and to the further fact that whatever oxygen may be contained in the cup or inner cylinder of the positive electrode is speedily consumed, and the resultant or remaining gas or vapor, of whatever character it may be, rising or tending to rise by reason of its heated state, fills and occupies the entire interior of such inner cylinder or cup, and completely envelops the inclosed extremity of the negative electrode, thereby precluding the ingress of oxygen, or the contact of such oxygen with the arc, the vapor thereof, or the crater. Not only is the hissing suppressed or eliminated, but with this arrangement of the electrodes, after striking the arcs the electrodes may be gradually separated, makmg the arcs longer and drawing more current without causing hissing thereof, provided the voltage be adequate. I have also found that with a current of five hundred Yolts or more, and with arcs of from one to one and one-half inches, with seven to ten amperes, the results at a distance are improved, and that the electrodes can be adusted and the consequent arcs varied without producing the hissing sound. When several arcs are formed or burning in series, and the voltage is sufficient only to maintain them, even though the separation of the electrodes be as slight as a quarter of an inch or less, it is found that if air comes in contact with the positive electrode, and the crater runs up the side thereof and hissing begins, such are absorbs more than its proper proportion of the electromotive force, there is a decrease of potential in the other arcs, and they cease or go out. If there be a surplus of voltage or pressure, this action does not take place. Articulate speech can be and has been clearly and distinctly transmit ted and received by apparatus constructed as above set forth, without the use of wires or other conductors between the transmitting and receiving points. The same construction and arrangement is adopted for each pair of electrodes, and by reason of suppression of the hissing with its attendant effects, I am enabled to maintain in proper arcing condition and for prolonged periods of time, a considerable number of pairs of electrodes, arranged in series as above described, and to vary the length of such, arcs wlthin wide limits, Without causing hissing.

In addition to the parts already described, I provide means for tuning the apparatus.

This consists of an inductance 83 in the form-of a hollow drum or cylinder wound onits exterior with a quite considerable leiigth'of wire, here shown arranged in two A binding post 87 at the top of the cylinder connects with the upper end of the upper inductance section and a second binding post 88 is connected with the lower extremity thereof. Similarly, binding posts 89 and 90 connect with opposite ends of the lower inductance, and the posts 88 and 89 are, normally, electrically connected. At suitable intervals, conveniently at every fifth coil of the wire, a contact stud or button 91 is brought to the surface of a bar or strip 92, with which buttons contact is made by a sliding contact plate 85 movable upon a rod 86 extending from top to bottom of the cylinder, as seen in Fig. l, the plate 85 being capable of making contact with any one of the studs or stems 91, and thereby including whatever number of coils of wire may be deemed desirable.

The purpose of making the inductance in two sections is immaterial to the present application, and the winding may be continuous from top to bottom of the cylinder, and the intermediate binding posts 88 and 89 may be omitted without in any manner affecting the invention here described.

The inductance cylinder 83 is also conveniently made of dimensions to permit it to encompass the tank 30 and the series of electrodes 12, 13, 11, 15, 16 and 17, which in practice I find it convenient to arrange in a circular series, the lower extremity of the inductance drum resting upon a ledge or support on the framework which carries the electrodes and the tank or reservoir 30. This ledge or support is seen in Fig. 3, which shows also the general framework or support for the electrodes, tank, etc.

In Figs. 5 and 6 I have illustrated a convenient arrangement of the telephone and microphone transmitters, transformers, etc., and their inclosing cabinets or casings. The transmitters 53, 54, 55, 56, 57 and 58, and the open-core transformers 67, which may stand for or represent the series of transformers 10 to 51, inclusive, of Fig. 1, and the two condensers 38 and 39, are here represented as carried upon a commonbacking or board, which is in turn carried by a main board or support, over which, as shown in Fig. 6, suitable boxes or casings are applied to protect the parts from dust and exposure, the mouthpiece 59 and bell 60 of the megaphone alone protruding through such shell or casing.

To One, side of the parts just described is arranged an automatic switch 70, comprising an elbow lever 72, the horizontal arm of which has a hook-shaped end 71. The lever is fulcrumed at 73 at the junction of its two arms, and the extremity of its upright arm is pivotallyconnected to a sliding block 74 of vulcanite or similar insulating material, suitably guided, and carrying at its opposite vertical edges conducting strips 76 and 77, designed to make, alternately, electrical connection between separated contacts 78 and 79, and between similar contacts 80 and 81 arranged on opposite sides of an open space 75, across which the block 74 is movable. The horizontal arm of lever 72 is normally depressed or held down by the Weight of a receiving telephone, one or more, hung upon hook 71, acting in opposition to the lifting tendency of a spring 82, or equivalent lifting means. From this it follows that so long as the lever 72 is in its lower or depressed position, the strip 77 will bridge the contacts 80 and 81, while upon the removal of the receiving telephone from the hook, or release of said lever from the depressing force, it will rise, and cause the block 74 to move to the right, whereupon the strip 76 will bridge the contacts 78 and 79. Circuits may thus be established through suitable receiving or signaling devices when the lever is in one position, and through the transmitting devices when the lever is in the other position. The switch 61 serves to cut in or out the microphone.

Upon talking into the mouthpiece of the microphone, while the circuit including the choke coil and transformer primary is energized, speech is transmitted through the secondary of the transformer, the variable condenser and inductance, to the antennae and ground, the waves radiating from the antennae through space and being taken up by receiving or translating instruments in a similar outfit at a distant point. The circuit is tuned by opening and closing the condenser, and by varying the inductance and capacity.

Though I have shown and described a telephonic transmitting apparatus, it is to be understood that this is merely illustrative, and that a telegraph key may be introduced in lieu of or in addition to the telephonic instrument. Similarly, other known devices may be substituted, and used with various translating devices at the distant point or points.

The transformer, of which the primary and secondary are respectively indicated by 4 and 33, Fig. 1, is designed to step up the potential. and hence employs relatively coarse wire for the primary and relatively fine wire for the secondary, and a relatively great length of wire in the secondary. The ratio will, of course, be determined by other working conditions, such as the initialienergizing current, number of oscillations, etc.

It is found that with the arcing end of the negative electrode introduced into and encompassed by the positive electrode, the

latter being kGPI- COOl, hissing of the arcv Qassingbetween them is speedily and permanently": suppressed, provided usual working adjustments and conditions be properly maintained in the remainder of the apparatus. The end of the negative electrode preserves a more symmetrical form than when the arc passes in an atmosphere of, or containing oxygen, and there is apparently merely a vaporization ofthe wasting electrode instead of actual combustion, such as occurs when oxygen is present. The domeshaped cavity of the positive copper electrode corresponds somewhat closely to the crater which forms at the end of a carbon electrode when used in like position and relation. Occupying the end only of said electrode, and maintained at such point, this conduoes to silence of the are; it being well known that so long as .the crater maintains its position at the end of the electrode and is prevented from climbing the side thereof, silence is maintained, or hissing is prevented. By the peculiar form and arrangement of electrodes above described, and by cooling the copper electrode, I apparently reproduce, control, and maintain the conditions which obtain when the are between two carbon electrodes is silent.

By the apparatus above described I am enabled to produce an alternating current of cycles ranging from audibility, that is below thirty-eight thousand alternations per second, to five hundred thousand or more per second, without the use of hydrogen or other gas, the number of alternations depending upon the amount of current used. In proportion to the increase in current and voltage employed in the oscillating, or tuned, or antennae circuit, up to a point at present undetermined,or in other words, the more energy radiated,the farther can talking or signaling be done if the arcs be maintained in arcing relation or condition, as above set forth.

The details of construction of various parts of the apparatus may be modified, and some of them will be. The present description is, therefore confined to what is necessary to a proper understanding and use of the broader invention herein claimed.

Having thus described my invention, what I claim is:

1. In an apparatus for wireless transmission of energ employing a pair of arcing electrodes for production of oscillations in the energizing circuit, the combination of a hollow metallic electrode having a chamber or cavity in its arcing end, the axial measurement of which is at least equal to its transverse diameter, and a negative electrode having its hemispherical end introduced within said cavity and substantially in the focal point thereof.

2. In apparatus for wireless transmission of energy, employing arcing electrodes for producing oscillations in the energizing ciremit, a pair of electrodes, one of which is suflieient to cause the arc forming between provided at its arcing end with a cavity, and them to be completely encompassed by the the other of which has its end projected into walls of the cavity.

said cavity, the cavity being of such axial FREDERICK HOYER MILLENER. measurement and the two electrodes of such lVitnesses:

relative diameters as to permit the one to eX- MURRAY SCHWARTZ,

tend into the cavity of the other a distance CHARLES P. Ross. 

